Die for cutting screws



(No Model.) f

Gr. HOLSTEIN.

DIE POR CUTTING SCRBWS.

No. 350,366. Patented Oct. 5, 1886.

WITNESSES WOR/w? Ys N. PLTERa pmu-unwwplw. wmingwr. D. c;

I UNITED STATES PATENT OFFICE.

GEORGE HOLSTEIN, OE sPUYTEN DUYvIL, :NEW YORK.

on: FOR CUTTING scREws.

SPECIFICATION forming part of Letters Patent No. 350,365, dated October5, 1886.

Application tiled June 171S6. Serial No. 205,447. (No model.)

'To ail whom it may concern:

'Be it known that I, GEORGE HOLSTEIN, a citizen of the United States,residing at Spuyten Duyvil, in the county of New York and State of NewYork, have invented new and useful Improvements in Dies for CuttingScrews, of which the following is a specification.

rlhis invention relates to dies for cutting screw-threads; and itconsists in certain novel features of construction, which'are full ypointed out in the following specification and claims,

vand illustrated in the accompanying drawings,

in whichf- Figure l is a plan view of myv/die, showing it secured in awrench. Fig. 2 is a cross section of the same in the planeadas, Fig. l.v Fig. 3 is a bottoni view. Fig. 4 is a horizontal section in the planeg/ y, Fig. 2. Figs. 5 and 6 are views of a modified form of cutting-hub.

Similar letters indicate corresponding parts.

In the drawings, the letter1 A designates the die-plate, which carries anumber of radiallyadjustable cutting-hubs, B, which are arranged arounda central opening in said die-plate, which will permit the passage ofthe article on which the thread is to be cut. Each of the hubs B isprovided with two or more available cutting-edges, a, and is rmlymounted on a hollow bushing, b, by means of a feather-key, c. In thelower end of this bushing is cut a series of ratchetteeth,,corresponding in number to the number of cutting-edges on thehub, and soarranged that the front face of each such tooth comes directly under oneof the cuttingedges. (See Fig. 6.) The ratchet-teeth on the ybushing bengage corresponding teeth, j, cut

into the upper surface of a hollow guide-block, d. -This guide-blockrests on a slide, e, which is fitted into a groove, f, in the undersurface of the die-plate A.

All the above parts are connected and held together by a screw, g, whichpasses through the hub B, the bushing bfand the guide-block d, and istapped into the slide e, the'whole being arranged to be radially adjusted by means of the set-screw h, which is threaded in the die-plate.W'hen the proper adjust-nient for the cutting-hub and the partsconnected to the saine has been found, they can be firmly held inposition .by tightening the screw g, which serves to clamp thecutting-hub* against the face ofthe die-plate. The threads on the screwsg are, by preference, left-handed if the threads Aon the cutting-hub areright-handed, and vice versa.

The cutting hubs B may be either made of one Vpiece of metal, in whichthe cutting-edges have been formed by'means of grooves or recesses, asshown in Figs. l and 2, or the cutting-edges may consist of insertedcutting blades or chasers,7 as shown-in Figs. 6 and 7, the latter methodof construction being preferred where the cutting-hubs are of a largersize and intended for heavy work.

rlhe threads in the cu tting-edges of the hubs are formed by placing thehubs B, into which grooves m have been previously cut, in properposition on the dieplates and tapping the same in the usual way by a tapor thread cutting hub, the advantage of this method being that the teeththus formed on the cutting-edges of the various hubs will at once be inproper point, and then again tighten these screws.A

To insure the proper placing of the cuttingedges during this operation,I have provided the above-described ratchet-teeth, both on the bushing band the guide-block el, the relative position of these teeth and thecutting-edges being such as always to insure the most effective positionfor the cutting-edges.

When desired, all the cutting-edges on the cutting-hubs can be -formedto cut the same thread, so that when one of these edges becomes dull oris broken it can be replaced by turning that hub and bringing one of theother cuttingedges thereon to the cutting position.

If it is found necessary to move all the cutting-hubs toward or from thecenter simultaneously, any -of the devices generally used in what isknown as universal lathe-chucks may be applied to the slides e; but Iprefer the form shown in the drawings.

What I claim as new, and desire io secure by Letters Patent, is-

1. The combination, with the dic-plate A and a series ofradiallyadjnstable slides, c, of the tubular hubs B, each having aseries of available cnttiligedges, and the screws g, passing through thehubs and tapped into the adj ustable slides, substantiall y asdescribed.

2. The combination, with a hub for cutting screw-threads on bolts, saidhub being provided with two or more available cutti 11g-edges, of theratchet-teeth i, formed on said hub, the ratchet-teeth j, and adic-plate, A, carrying the ratchetteeth j, substantially as described.

3. The combination, with a hub for cutting screw-threads on bolts, saidhub being provided with two or more available cu ttinged ges, of thebushing b, ratchettectll 17, formed on said bushing, the ratchet-teethj, and a dieplate, A, carrying the ratchet-teethj, snbstantially asdescribed.

4. The combination, with a die-plate, A, of4

three or more hubs, B, cach of which is provided With two or moreavailable cutting-edges, and means, substantially as described, forradially adjusting all the hubs on said die-plate, substantially asdescribed.

5. The combination, with a die-plate, A, of two or more cutting-hubs, B,each of which is provided with two or more available cuttingedges, ofthc bushing b, ratchetteeth t', formed on said bushing, the guide-blockd, ratchetteeth j, formed in said guide-block and adapt- 35

